The present invention relates to methods of manufacturing cushion constructions for seating, where the cushion has improved cushioning properties.
Chairs having upholstery covered cushions on their seat and backs are known. The cushions provide a cushioning effect that conforms at least somewhat to a seated user's body to provide increased comfort. A common cushion in chairs is a polyurethane open-celled foam cushion that is pre-formed to an initial shape. For example, U.S. Pat. No. 4,718,153, to Armitage et al., issued Jan. 12, 1998, entitled Cushion Manufacturing Process, discloses one such cushion manufacturing process utilizing a polyurethane foam. A problem is that the polyurethane will degrade over time, leading to breakdown of the polyurethane foam that generates dust and a degradation of cushioning properties. The dust and breakdown potentially adds to environment dust in the building where the chair is located. Also, the breakdown and loss of material results in changes to the cushioning support provided by the cushion. Polyurethane foam cushions also suffer from other disadvantages. Polyurethane foam is not recyclable, leading to increased landfill costs when scrap is generated. Further, the polyurethane foam typically has a pinched-off edge or weld line of higher density material running around its perimeter. The higher density material can cause quality problems, both in terms of poor appearance due to its roughness, stiffness, and protruding nature, and also in terms of an unattractive bumpy feel when a person sits on or feels the fabric covering the higher density material. Still another problem is caused when a seated user sweats against a polyurethane foam cushion, because the polyurethane foam cushions are sometimes not able to wick away the sweat (or at least not fast enough), depending on the foam and the volume of sweat.
Accordingly, an improved cushion construction for furniture is desired that solves the aforementioned problems and has the aforementioned advantages.